Total shoulder replacement or arthroplasty may be indicated for those with severe arthritis, a fractured proximal humeral, or other complications. There are different types of arthroplasty procedures that may be performed depending on the patient. For example, total shoulder arthroplasty generally involves replacing the damaged bone and cartilage with an implant. For a conventional shoulder arthroplasty, a metal implant having a head is positioned within the humerus, and a polymeric socket is implanted within the scapula. A hemiarthroplasty involves replacing only one half of the shoulder joint, which may be suitable for patients with proximal humeral fractures. Another technique for replacing the shoulder is a reverse shoulder arthroplasty where the location of the head and socket are reversed, which may be indicated for patients that have completely torn rotator cuffs.
Proximal humeral fractures treated with arthroplasty continue to be challenging for the orthopedic surgeon. One of the difficulties is the amount of proximal humeral bone loss, which must be compensated for in selecting final component position. Previous systems have attempted to address these issues by incorporating a jig system to compensate for these anatomical deficiencies. For example, U.S. Pat. No. 6,277,123 to Maroney et al. discloses one such jig system employing a clamp that attaches to the humeral shaft. However, there are difficulties that remain even with this jig in place both for hemiarthroplasty and reverse shoulder arthroplasty in the treatment of cases with proximal humeral bone loss. First, utilization of this jig requires a more extensive surgical dissection to seat the jig. Second, the jig is by nature quite bulky and unwieldy in the surgical wound. Third, the alignment apparatus is not configured for utilization in reverse arthroplasty. Fourth, the amount of force required to reduce a reverse arthroplasty is much greater than in a hemiarthroplasty application. This amount of force may cause the jig to fail at either the implant interface or bone interface.
Thus, there remains a need in the art for an improved system for treating proximal humeral fractures. In particular, there is a need for less complex and bulky system. In addition, there is a need for a system that is applicable to both hemiarthroplasty and reverse arthroplasty that builds off the existing shoulder platform.